In emulsion polymerization field, if emulsion or inverse emulsion is obtained with an appropriate surfactant, the product quality of the application system will be greatly improved; however, the residual surfactant after polymerization reaction will result a series of problems. Up to now, some polymerizable surfactants applicable to emulsion polymerization have been proposed in many patent literatures. For example, U.S. Pat. No. 4,939,283 discloses a polymerizable surfactant obtained from the reaction between a conventional non-ionic surfactant and allyloxyglycidol ether; U.S. Pat. No. 5,296,627 discloses an ethylene terminated allyloxypolymerizable surfactant; U.S. Pat. No. 6,649,718 discloses a polymerizable surfactant obtained from the reaction between long-chain alkylene oxide and allyl alcohol; U.S. Pat. No. 7,026,418 discloses a surfactant prepared from a copolymer of alkylene oxide with polymerizable double bonds and glycidol ether; CN102489215A discloses an amphoteric reacting surfactant; CN101982224A discloses a polymerizable surfactant that contains allyl or methyl allyl and is obtained by etherification between a glycidol ether compound and allyl alcohol or methyl allyl alcohol and follow-up epoxy addition.
In the petroleum drilling course, the encountered formations are more and more complex, and exceptional wells, ultra-deep wells, and complex wells increase with years, bringing higher requirements for the drilling fluid. In the development of unconventional oil and gas, typically shale gas, 60%˜70% horizontal wells of shale gas in foreign countries employ oil base drilling fluid systems for well drilling, to meet the requirement for well wall stability, lubrication and sticking prevention. However, water-based drilling fluids are the best choice, because oil-based drilling fluids have high cost and environmental pollution problems. It is found in researches that active shale suffers water loss (or dehydration) in dense CaCl2 solution, therefore, it is necessary to study the application of water-based CaCl2/polymer drilling fluids for horizontal drilling of shale gas for the purpose of cost reduction and environmental protection. Since linear polymers can't fully meet the requirements of well drilling owing to the fact that their tackifying ability is degraded under high-salinity conditions, a key task in the development of water-based CaCl2/polymer drilling fluids is to develop a polymer treating agent applicable to water-based CaCl2/polymer drilling fluids.